Design and construction of a 3.0 Tesla high resolution superconducting magnet system with short horizontal 30cm bore to incorporate with Phospho-Energetics, Inc. phosphorous nuclear magnetic resonance spectrometer. Preliminary work has been performed at the University of Pennsylvania, Department of Biochemistry using 1.5 and 1.9 Tesla superconducting magnets for variety of in vivo studies of various diseases in animal model and humans. Relevant to this proposal are studies in animal model tumors and therapy thereof to follow their time courses non invasively. In addition, neuroblastoma tumors of the liver have been studied in infants and children as well as tumors on limbs of adults. Unlike 1H NMR imaging which yields anatomical data with limited specificity, 31P NMR yields direct measurement of metabolism that precedes anatomical changes. Unfortunately, 31P is present in very low concentrations, 10-20mM compared to protons at 100M, and is therefore much more difficult to detect. P-E has pioneered in the application of 31P NMR instrumentation to in vivo measurements of various metabolic disorders. More recently high resolution proton NMR where the bulk water signal is suppressed yielding underlying high resolution spectra of the same phosphorous metabolites plus lactate has indicated that observation of 31P and high resolution 1H would yield more useful information on the metabolism of tumors.